The invention relates to a method for authentication of a person on the basis of the person's voice profile, as well as to a corresponding authentication arrangement.
Previously used methods of authenticating a person are based on checking whether the person is in possession of particular objects (traditionally, e.g., a seal or pass, recently also an admission card or token) or of individualised knowledge (e.g., PIN or password). Biometrically based authentication methods, on the other hand, make use of certain physical characteristics of the person, such as a fingerprint or retinal pattern, or a voice profile.
In recent years extensive work has been done to develop the last of these methods, which has already resulted in marketable products. In relation to these developments, considerable attention has been paid to the question of how useful “traces” of the person can be for authentication or even an initial registration (so-called enrollment), both with regard to the security of identification or authentication and with regard to user acceptance, i.e. the avoidance of long and elaborate procedures.
With methods of this generic kind an important aspect is the usefulness of the speech samples so obtained for registration or authentication of the user, and any resulting control influences upon the way the procedure is carried out. Of special significance for the practical acceptance and hence the commercial adoption of the methods concerned is that a level of security prespecified by the system user can be reliably achieved.
An additional object of the developments is therefore to establish measures that can be employed in case this degree of security is not achieved, because of problems that occur in practice with either the vocal material or implementation of the method. Such problems can reside, for instance, in the current physical and mental state of the speaker, in the presence of background noises and in a low quality of the transmission channel or of the device into which the speech sample is spoken.